The invention relates to a drill, in particular to a rock drill with a drill head equipped with a hard metal insert.
A drill of this kind is known from DE 197 27 070 C2. This drill with a core reinforcement in practice has turned out to be particularly efficient and durable.
This type of drill is still used today as a so-called four-flute cutter and offers the possibility to combine a good stability and a relatively large drill dust removal groove. The core reinforcement makes it possible to work with a quite thin core resulting in a correspondingly large drill dust removal groove, but nevertheless on the other hand makes it possible to reduce the tendency to break due to the effected reinforcement of the core.
By core reinforcement a convexity in the direction of the drill longitudinal axis is understood, that is to say a convex structure of the drill core within each drill dust removal groove if viewed at a longitudinal section of the drill.
On the other hand, the invention is based on the object of providing a drill, whose long-term stability and resistance to breakage are still further enhanced.